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71.
72.
Malcolm A. Halcrow Colin A. Kilner Mark Thornton‐Pett 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1425-1426
The title compound, [Zn(C29H29N5)2](ClO4)2·2CH3NO2, contains a ZnII ion showing only small deviations from local D2d symmetry. The lower rhombicity exhibited by this complex compared with that of its CuII congener suggests that the highly rhombic stereochemistry exhibited by the latter is largely imposed by the stereoelectronic preferences of the CuII ion. 相似文献
73.
Gooding KB Higgs R Hodge B Stauffer E Heinz B McKnight K Phipps K Shapiro M Winkler M Ng WL Julian RK 《Journal of the American Society for Mass Spectrometry》2004,15(6):884-892
Approximately 300,000 compounds from selected libraries were screened against a subdomain of a hepatitis C viral (HCV) RNA using a high throughput flow injection mass spectrometry (FIA-MS) method with automated data storage and analysis. Samples contained 2 microM RNA target and 10 microM of each of up to ten ligands. Preliminary studies to optimize operational parameters used the binding of aminoglycosides to the A44 subdomain of bacterial RNA. Binding (confirmed by titration) and sensitivity were maximized within the constraints of the library and throughput. The mobile phase of 5 mM ammonium acetate in 50% isopropanol maintained the noncovalent complexes and provided good detection by electrospray mass spectrometry. Additionally, this composition maximized general solubility of the various classes of compounds including the oligonucleotide and organic library molecules. Cation adduction was insignificant in this screen although some solute and target dependent acetate adduction was observed. The ion trap mass spectrometer provided sufficient mass resolution to identify complexes of RNA with known components of the library. Converted mass spectral data (netCDF) were subjected to two types of statistical evaluation based on binding. The first algorithm identified noncovalent complexes that correlated with the molecular weights of the injected compounds. The second yielded the largest peak in the noncovalent complex region of the spectrum; this spectrum may or may not correlate with expected well components. Sixty-three compounds were confirmed to bind by more stringent secondary testing. Titrations, which were carried out with selected binding compounds, yielded a range of dissociation constants. Biological activity was observed for eleven confirmed binders. 相似文献
74.
75.
Henkelis JJ Kilner CA Halcrow MA 《Chemical communications (Cambridge, England)》2011,47(18):5187-5189
Recrystallisation of Ag[L(1)] (HL(1) = 3{5}-[pyrid-2-yl]-5{3}-tert-butylpyrazole) in the presence of halide anions leads to two polymorphs of [Ag(3)(μ-Br)(μ-L(1))(2)], which differ in their mode of supramolecular association, and the cluster [Ag(10)(μ-L(1))(8)]Cl(2). In contrast, Ag[L(2)] (HL(2) = 3{5}-[isoquinol-1-yl]-5{3}-tert-butyl-pyrazole) crystallises as a cyclic tetrameric molecule. 相似文献
76.
Ke J Bartlett PN Cook D Easun TL George MW Levason W Reid G Smith D Su W Zhang W 《Physical chemistry chemical physics : PCCP》2012,14(4):1517-1528
Several Ge(II) and Ge(IV) compounds were investigated as possible reagents for the electrodeposition of Ge from liquid CH(3)CN and CH(2)F(2) and supercritical CO(2) containing as a co-solvent CH(3)CN (scCO(2)) and supercritical CH(2)F(2) (scCH(2)F(2)). For Ge(II) reagents the most promising results were obtained using [NBu(n)(4)][GeCl(3)]. However the reproducibility was poor and the reduction currents were significantly less than the estimated mass transport limited values. Deposition of Ge containing films was possible at high cathodic potential from [NBu(n)(4)][GeCl(3)] in liquid CH(3)CN and supercritical CO(2) containing CH(3)CN but in all cases they were heavily contaminated by C, O, F and Cl. Much more promising results were obtained using GeCl(4) in liquid CH(2)F(2) and supercritical CH(2)F(2). In this case the reduction currents were consistent with mass transport limited reduction and bulk electrodeposition produced amorphous films of Ge. Characterisation by XPS showed the presence of low levels of O, F and C, XPS confirmed the presence of Ge together with germanium oxides, and Raman spectroscopy showed that the as deposited amorphous Ge could be crystallised by the laser used in obtaining the Raman measurements. 相似文献
77.
Gerald G. Miller Kevin Brown Ronald B. Moore Malcolm S. McPhee Zhenjun J. Diwu Jixiang Liu Liren Huang J. William Lown David A. Begg Vera Chlumecky John Tulip 《Photochemistry and photobiology》1995,61(6):632-638
Hypocrellins are naturally occurring compounds with photosensitizing properties in biological systems. We have prepared synthetic derivatives of hypocrellin B, which have promise as photosensitizers in the clinical application of photodynamic therapy. The intracellular localization and uptake kinetics of hypocrellin B and several selected hypocrellin congeners were determined semiquantitatively by fluorescence confocal microscopy in monolayer cultures of EMT6/Ed murine tumor cells. Each compound had unique uptake kinetics. Although no compound tested to date has demonstrated nuclear labeling, most could be detected in lysosomes, Golgi, endoplasmic reticulum and, to a minor extent, in cellular membranes. No two compounds gave identical labeling distributions. The differences are assumed to originate in physicochemical properties characteristic of each compound, which may ultimately impact upon the primary modality of phototoxicity. 相似文献
78.
79.
Szostak M Collins KD Fazakerley NJ Spain M Procter DJ 《Organic & biomolecular chemistry》2012,10(30):5820-5824
Herein we describe a strategy for the selective, electron transfer reduction of lactones of all ring sizes and topologies using SmI(2)-H(2)O and a Lewis base to tune the redox properties of the complex. The current protocol permits instantaneous reduction of lactones to the corresponding diols in excellent yields, under mild reaction conditions and with useful chemoselectivity. We demonstrate the broad utility of this transformation through the reduction of complex lactones and sensitive drug-like molecules. Sequential electron transfer reactions and syntheses of deuterated diols are also described. 相似文献
80.
Simple binary solids can be found to adopt unprecedented structures when confined into nanometre-sized cavities, such as the inner cylindrical bore of single-walled carbon nanotubes (SWNT). In the case of the discussed Lal(x)@SWNT encapsulation composite, the Lal2 "crystal" fragment adopts the structure of bulk Lal3, with one third of the iodine positions unoccupied. A complete characterisation of the encapsulation composite was achieved using an enhanced digital restoration approach of high-resolution transmission electron microscopy (HRTEM) images. The resulting complex exit surface wave provides information about the precise structural data of both filling material and host SWNT, establishing the SWNT's chirality and thus enabling a prediction of the composite's overall electron-transport properties. 相似文献